Light drinking in pregnancy not bad for children, says UCL study

Publication date:
Oct 31, 2008 12:01:29 PM

Children born to mothers who drink lightly during pregnancy
– as defined as 1-2 units per week or per occasion – are not at increased risk
of behavioural difficulties or cognitive deficits compared with children of
abstinent mothers, according to a new study led by researchers at UCL
(University College London).

The research, based on data from the UK Millennium Cohort
Study (MCS), is published today in the International
Journal of Epidemiology. It uses data on 12,495 three year-old children, looking
at the mothers’ drinking patterns during pregnancy and assessments of the behavioural
and cognitive outcomes of their children.

Lead author Dr Yvonne Kelly, UCL Epidemiology & Public
Health, said: “The link between heavy drinking during pregnancy and consequent
poor behavioural and cognitive outcomes in children is well established.
However, very few studies have considered whether light drinking in pregnancy
is a risk for behavioural and cognitive problems in children.

“Our research has found that light drinking by pregnant
mothers does not increase the risk of behavioural difficulties or cognitive
deficits. Indeed, for some behavioural and cognitive outcomes children born to
light drinkers were less likely to have problems compared to children of
abstinent mothers, although children born to heavy drinkers were more likely to
have problems compared to children of mothers who drank nothing whilst pregnant.”

The study data shows that boys born to mothers who drank
lightly were 40 per cent less likely to have ‘conduct’ problems and 30 per cent
less likely to have hyperactivity, even when a range of family and socioeconomic
factors were taken into account. Boys born to light drinkers also had higher
scores on tests of vocabulary and whether they could identify colours, shapes,
letters and numbers compared to those born to abstainers.

Girls born to light drinkers were 30 per cent less likely to
have emotional symptoms and peer problems compared with those born to
abstainers, although this appeared partially explained by family and social
backgrounds.

Dr Kelly continued: “The reasons behind these findings might
in part be because light drinkers tend to be more socially advantaged than
abstainers, rather than being due to the physical benefits of low level alcohol
consumption seen, for example, in heart disease. However, it may also be that
light-drinking mothers tend to be more relaxed themselves and this contributes
to better behavioural and cognitive outcomes in their children.”

The UK
currently does not recommend complete abstinence from alcohol for the duration
of pregnancy and there are inconsistencies in policy statements from the
National Alcohol Strategy and the National Institute for Health and Clinical
Evidence (NICE), which may cause confusion for health professionals and the public.

A recent review carried out by the National Perinatal
Epidemiology Unit (NPEU), and a statement from the Royal College of
Obstetricians and Gynaecologists (RCOG) highlighted the need for studies
focusing on the effects of light drinking, and for investigators to use
population-based data, as the researchers have done in this study.

Dr Kelly added: “There is inconsistency in policy around
this issue and studies such as this one are vital in light of the wider debate
around drinking and pregnancy. Our study’s findings do raise questions as to
whether the current push for policy to recommend complete abstinence during
pregnancy is merited and suggest that further research needs to be done.”

2.) ‘Light drinking in pregnancy, a risk
for behavioural problems and cognitive deficits at 3 years of age?’ is
published online ahead of print on Friday 31st October 2008 in the International Journal of Epidemiology.
For copies of the paper, go to: http://ije.oxfordjournals.org/cgi/reprint/dyn230v1

3.) The Millennium Cohort Study (MCS) is funded
by the Economic and Social Research Council (ESRC) and a consortium of
Government Departments. This research is supported by an ESRC grant - code
RES-596-28-0001.